As night the life-inclining stars best shows,
So lives obscure the starriest souls disclose.
(Hymns and Epigrams of Homer – George Chapman)
Listening to an episode of Melvyn Bragg’s In Our Time radio programme recently, I learned that the first person to postulate the existence of black holes was not, as I’d always assumed, some twentieth-century genius like Albert Einstein or Stephen Hawking, but an eighteenth-century scientist called John Michell. Having searched out Michell on the Web, I found him referred to invariably as an ‘obscure clergyman’.
While Michell may have become obscure in the centuries after his death, he achieved a certain position in his own time. A fellow of Queen’s College, Cambridge, he lectured in arithmetic, geology, geometry, Hebrew, and Greek, as well as astronomy. He became a member of the Royal Society and was eventually appointed Woodwardian professor of geology at Cambridge. The attribution of obscurity is more relevant to the last stage of his life, when he moved to Yorkshire to become rector of Thornhill.
What about those black holes? In November 1783, Michell presented a paper to a meeting of the Royal Society in which he argued, using Newton’s theories concerning gravity and corpuscular light, that the universe might contain stars whose gravitational pull was so strong that light could not escape them. Michell called these bodies dark stars rather than black holes, but the principle was the same. Michell’s paper, ‘On the means of discovering the distance, magnitude, &c. of the fixed stars, in consequence of the diminution of the velocity of their light, in case such a diminution should be found to take place in any of them, and such other data should be procured from observations, as would be farther necessary for that purpose’, was published in the Philosophical Transactions of the Royal Society of London the following year and then, initially lacking any support from observation or experimentation, remained semi-hidden in the archives until the 1970s.
In the meantime, Albert Einstein published his theory of general relativity in 1916 and another physicist called Karl Schwarzschild used those equations to propose the existence of black holes, though the term wasn’t coined until 1968.
Michell is a bit of a dark star himself. No portraits of him survive and as far as I know he has no biography, other than short entries in the likes of the ODNB and Wikipedia. He was described by one contemporary as ‘a little short Man, of a black Complexion, and fat…he continued Fellow of Queen’s College, where he was esteemed a very ingenious Man, and an excellent Philosopher. He has published some things in that way, on the Magnet and Electricity’. He remains an almost forgotten figure, though he is as well-known now as he has ever been since his death. Still, it is a remarkable thing that a man living almost two hundred and fifty years ago could have anticipated the notion of black holes. The reach of human reason is so often astonishing. Perhaps even more astonishing is the fact that a species of primate that was living a hunter-gatherer existence just ten thousand years ago can explicate such a notion. How, really, is that even possible?
[Image of Joseph Wright’s painting A Philosopher Lecturing on the Orrery courtesy of Wikimedia Commons.]